Mattress



FIG. 1 is an isometric view of a top, front, and right side of an ornamental design for a mattress;

FIG. 2 is a front elevational view of the mattress of FIG. 1;

FIG. 3 is a rear elevational view of the mattress of FIG. 1;

FIG. 4 is a right side elevational view of the mattress of FIG. 1;

FIG. 5 is a left side elevational view of the mattress of FIG. 1;

FIG. 6 is top plan view of the mattress of FIG. 1; and,

FIG. 7 is a bottom plan view of the mattress of FIG. 1.

It is understood that the dashed clover-like surface pattern and the vertical dash-dash-dash-dash broken lines on the sides of the mattress represent a pattern on the surface of the mattress that forms no part of the claimed design. Further, the remaining dash-dash-dash-dash broken lines represent environmental structure that forms no part of the claimed design. The dash-dot-dash-dot broken lines depict a mattress with a symbolic break in its length and width and forms no part of the claimed design. The appearance of any portion of the article between the symbolic break lines forms no part of the claimed design. Further, the dotted pattern bounded by the solid and dashed lines on the sides of the mattress in FIGS. 1 and 4-6, and the crosshatching on the sides, top, and bottom of the mattress in FIGS. 1-7 depict portions of the mattress and form no part of the claimed design. 

CLAIM The ornamental design for a mattress, as shown and described. 